Lubricating oil



Patented Mar. 7, 1939.

UNITED STATES PATENT orncs Ill., assignors to Leo Corporation, a corporation of Illinois Application October 12, 1935, Serial No. 44,682

No Drawing.

Chicago, 111-,

2 Claims. (01. 87-9) This invention relates to a lubricating oil and more particularly to the use in internal combustion engines of a crank case oil containing a mixture of oil soluble metal compounds adapted to 5 reduce the formation of hard carbon in the engine.

It is well known that the formation of carbon in the engines of automotive vehicles and the like causes leaky valves, loss of compression, sticky valves, and other conditions tending to diminish the efliciency of the engine. The formation of hard carbon deposits within the engine, however, reduces the engine efliciency to a muchv greater degree than does the presence of soft or flaky carbon deposits. y

We have now found that by embodyinga suitable mixture of metallic compounds in the crankcase oil, the tendency of the oil to form hard carbon inithe combustion chamber is greatly diminished and in many. instances entirely eliminated. The metals that we have found suited for this purpose are those which are recognized as having, on the one hand, hydrogenating or dehydrogenating catalytic activity and, on the other hand, those capable of acting as oxidation catalysts. The use of mixtures of hydrogenating or dehydrogenating catalysts with oxidation catalysts in the crankcase oil reduces or even elimi-.

nates the formation of hard carbon in the combustion chamber.

It has heretofore been proposed to incorporate various metallic compounds in lubricating or transformer oils forthe purpose of preventing sludge formation during storage of such oils. To the best of our knowledge, however, it has not heretofore been known that the addition to crankcase oil of particular metallic mixtures would prevent the formation of hard carbon and thus increase the efhciency of internal combustion engines with which such oil might be used.

It is therefore an object of' this invention to provide a motor lubricating oil, such as the crankcase oil, having incorporated therein a mixture of metallic compounds soluble in the oil and adapted to' act as hydrogenation or dehydrogenation catalysts, and oxidation catalysts, respectively, under the conditionsto which the oil would normally be exposed in the operation of no an internal combustion engine, whereby the formation of hard carbon in the combustion chamber of the engine is prevented or largely reduced and the efl'iciency of the engine correspondingly increased.

Other and further important objects of this invention willbecome apparent from the following description and appended claims.

The present invention relates particularly to the treatment of a motor lubricating oil having a viscosity suitable for use in the crankcase and cylinders of an internal combustion engine. Such viscosities are, in general, lower than about 75 seconds Saybolt at-210. F. To such an oil there is added a mixture of oil soluble metallic compounds selected from metals of two groups, one group having catalytic activity in promoting hydrogenation and dehydrogenation processes, and

the other group comprising metals capable of acting as oxidation catalysts under the conditions that'obtain in the operation of internal combustion engines.

The metals in the first group are termed hydrogenation or dehydrogenation catalysts for the reason that they tend to promote these processes, the extent to which they act as hydrogenation or dehydrogenation catalysts. depending upon the temperatures and pressures to which they are exposed and the particular analysis of the mixture of hydrocarbons with which these metal compounds may be associated. It is our belief that the metal compounds of this first group may promote hydrogenation of the hydrocarbons of the particular lubricating oil with which they are used, or hydrogenation of such carbonaceous residues as may tend to form within the combustion chamber of theinternal combustion engines in which 'our lubricating oil is used. At the same time it seems likely that these same metal compounds of group 1 promote dehydrogenation of the saturated hydrocarbons of the fuel mixture through contact of such fuel mixture with the oil film on the walls of the cylinder of the engine. It will be appreciated, however, that the exact reactions and types of reactions taking place within an internal combustion engine during its operation are practically impossible of determination, so that we do not wish to be bound by any theories herein expressed.

Metals which we classify under the heading of hydrogenation or dehydrogenation catalysts in group 1 include platinum, palladium, cobalt, and nickel as the preferred ones for use in motor lubricating oils. Group 1, however, also includes such metals as uranium, zinc, molybdenum, copper, iron and tungsten.

The efiectiveness of compounds of these metals ofgroup 1 in reducing or eliminating the formation of hard carbon within the combustion chambers of internal combustion engines is greatly inmetals of groups 1 and 2 that are soluble in the lubricating oil in the desired concentrations, In general, the most satisfactory compounds to use are the metal derivatives of beta-diketones having the general formula, R-CO--CI-IR1COR11,

wherein R and R11 are hydrocarbon radicals which may also carry halogen atoms as substituents, and R1 is such a hydrocarbon radical or a hydrogen atom. We pr zfer to use a metallic derivative of acetyl acetone or propionyl acetone, but various other beta-diketones may be used, such as benzoyl acetone; or the alkyl, aralkyl or aryl homologues or these beta-diketones.

In addition to the metal derivatives of the betadiketones, metal compounds or derivatives of succinic, malic and malonic acids, of oxidized sugar acids and of phenols and their homologues may be used. ,Complex addition products of palladium and of platinum with diethyl sulphideand with diethyl selenide are likewise available for use, the formulae of these complex compounds being most probable the following:

Pd (Cal-I5) 2SC114 Pd[ (Cal-I5) 258C114 The various organo-metallic compounds above enumerated for use as hydrogenation or dehydrogenation catalysts, or for oxidation catalysts, may, in general, be dissolved directly in the motor lubricating oil to the desired concentration, which has been found to vary between 0.1 and 5.0 grams per quart of oil, expressed as combined metallic content. I

The following will serve to illustrate suitable examples of mixtures of metal compounds of groups 1 and 2 for use with motor lubricating Aluminum 0.3

It will be understood, of course, that the combined metal content of the catalysts in our lubrieating oil may be decreased or increased beyond the limits above given, depending upon the particular lubricating oil being used and its carbon forming characteristics, but in general it has been found satisfactory to use a combined metal content within the ranges specified. When platinum or palladium compounds are used, a much lower metallic concentration is effective, due probably to the much greater hydrogen absorbing power of platinum and palladium as compared with the other metals. Concentrations of platinum or palladium of from 0.001 gram to 1 gram metallic content per quart of oil have been found to be effective.

Of the various organo-metallic compounds that have been enumerated herein for use as catalysts in groups 1 or 2, we prefer to use those compounds of the metals that decompose at temperatures below 200 'C. under the conditions present in the oil film formed on the cylinder walls during the operation of an internal combustion engine. We believe that under these conditions the more easily decomposable metallic compounds are converted into the reduced metals themselves or into oxides ofthe metals that serve more efficiently as catalysts for the purposes indicated.

It will be understood that the incorporation of our catalysts into motor lubricating oils will show greatest advantages where the lubricating oil is to be used in high compression engines, that is, where the compression ratio is greater than 6 to 1. The effect of hard carbon formation in high compression enginesis more noticeable and results in greater loss of efllciency than in the case of low compression engines. Consequently, the reduc-.- tion or elimination entirely of the hard carbon deposits by the use of motor lubricating oils of our invention is particularly advantageous in the case of high compression engines.

We are aware that numerous details of the process may be varied through a wide range without departing from the principles of this invention, and we, therefore, do not purpose limiting the patent granted hereon otherwise than necm- 'sitated by the prior art.

We claim as our invention:

1. A motor lubricating oil comprising a mixture of beta-diketones of a metal selected from the group consisting of platinum, palladium, cobalt,

nickel, uranium, zinc, molybdenum, copper, iron and tungsten, and of a metal selected from the group consisting of cerium, thorium, zirconium, beryllium, barium, chromium, titanium, vanadium, cesium, boron, aluminum, and lanthanum.

2. A motor' lubricating oil having dissolved therein per quart of oil from 0.1 to 5.0 grams of metallic content in-the form of a mixture of a beta-diketone derivative of a metal selected from the group consisting of platinum, palladium, cobalt, nickel, uranium, zinc, molybdenum, copper, iron and tungsten, and a beta-diketone derivative of a metal selected from the group consisting of cerium, thorium, zirconium, beryllium, barium,

- chromium, titanium, vanadium, cesium, boron,

aluminum, and lanthanum.

LEO J. MCKONE. WILLARD EMLYONS. 

